Apart from staplers, some of the most commonplace home and office items are laser printers and photocopiers. People often perceive these two machines to be completely different from each other. After all, laser printers are used for printing documents straight from a file while photocopiers are used for reproducing already printed documents and are usually deemed much cheaper to use than laser printers. Unknown to many however, these two devices utilize the same technology called “xerography” and use the same consumable component called a laser toner cartridge. Furthermore, laser printing and photocopying are commonly referred to as dry printing.
A Brief History of Xerography and Toners
The xerographic printing process employed in laser printers and photocopiers was originally invented in the year 1938 by a man named Chester Carlson. Originally, the process was called electrophotography because Carlson first used the electrostatic printing technology with and for photography. His invention went through multiple changes throughout the years, and it was not until around two decades after the initial invention that xerography became usable for commercial printing purposes. From the name of the process itself, xerography means dry (xeros) writing (graphia). As such, laser printing and photocopying are sometimes also referred to as dry printing. This is mainly because devices using Carlson’s invention do not use liquid ink, but instead use powdered or dry ink called a toner. This dry ink is carbon-based and is mixed with various polymers before being placed inside a laser toner cartridge. Traditionally, only black pigments were available but modern technology has enabled the production of cyan, magenta, and yellow colors for use in colored laser printing.
From Original to Compatible
Over the years, toners have not only gone from black-and-white to colored, but also from being produced solely by printer and photocopier manufacturers to being produced by third-party suppliers. Cartridges produced by manufacturers of printers and photocopiers are called original cartridges. These are often bundled with printing and copying machines when they are first bought. On the other hand, cartridges that are produced by anyone other than the printer manufacturers are called compatible cartridges and are used as replacement for original the laser toner cartridge. The progression in laser and toner technology has enabled third-party suppliers to produce compatible cartridges that are cheaper in price compared to originals. Regular consumers can easily spot the difference between original and compatible cartridges. Apart from the obvious that compatible cartridges are unbranded and generic, the powders inside originals are always finer. This often results in sharper images and prints from original cartridges compared to approximately 72% of all compatible cartridges.
How Laser Printers and Photocopy Machines Work
Laser printers and photocopiers may also be referred to as dry printers. This would sound unusual if you are only familiar with the concept of inkjet printers which make use of liquid ink instead of dry, powdered ink as in laser toner cartridge. Both inkjet and laser or digital printing use heat to produce quality printed documents although they utilize heat in different manners. In the case of inkjet printing, heat from electrical pulses is used to stimulate metal resistors inside the cartridge. The conduction of heat through these metal resistors triggers an increase in ink volume which causes the ink to spray out of the nozzle. This results in ink transfer from cartridge to paper. Laser printing makes use of heat somewhat differently since a laser toner cartridge does not contain liquids.
Heat in digital printers and copiers is generated through the use of lasers, thus the interchangeable title of laser printing. The lasers are used to transfer impressions on select sections of paper in order to following the pattern of the text or image you want to print. This impression gives portions of the paper an electromagnetic charge opposite the charge of the toners. The fine powder particles, released from the laser toner cartridge, are attracted to the areas with an opposite electromagnetic charge. The toner then bonds with the paper in this manner and through the heat left and generated by the lasers. Once a document is printed or copied, the machine’s photoreceptors are cleaned by soft blades which usually made of plastic in order to ensure that excess toners are not left behind. Photoreceptors are like rollers and are the intermediaries between the lasers in a machine and the paper meant for printing. The toner in a laser toner cartridge cannot be used without photoreceptors and lasers. These three main elements make up the laser printing and copying system of dry printing.